Could anyone please help me with info on how to solve variants such as 147 etc? I tried the no 65 easy (!) one and am totally stuck with the circled and squared fields . . . . (how sad can it get)Many thanks

The Squares with a circle inside them must contain the numbers 1 to 3, so on puzzle 65, R5C5 is a square with a circle, so must contain 1, 2, or 3. It cant be 1 as there is a 1 in R1C5, and it can't be a 3, so it is a 2.

Similarly the Squares with Squares in them must contain numbers 4, 5, and 6.

Also blank squares contain the numbers 7, 8, and 9 --> look at R8C4

For 1, 2, 3 just look at Squares with circlesFor 4, 5, 6 just look at Squares with squaresFor 7, 8, 9 just look at blank/normal Squares.